Structural and Functional Brain Changes in Patients With Classic Trigeminal Neuralgia: A Combination of Voxel-Based Morphometry and Resting-State Functional MRI Study

Abstract

ObjectivesBrain structural and functional abnormalities have been separately reported in patients with classic trigeminal neuralgia (CTN). However, whether and how the functional deficits are related to the structural alterations remains unclear. This study aims to investigate the anatomical and functional deficits in patients with CTN and explore their association.MethodsA total of 34 patients with CTN and 29 healthy controls (HCs) with age- and gender-matched were recruited. All subjects underwent structural and resting-state functional magnetic resonance imaging (fMRI) scanning and neuropsychological assessments. Voxel-based morphometry (VBM) was applied to characterize the alterations of gray matter volume (GMV). The amplitude of low-frequency fluctuation (ALFF) method was used to evaluate regional intrinsic spontaneous neural activity. Further correlation analyses were performed between the structural and functional changes and neuropsychological assessments.ResultsCompared to the HCs, significantly reduced GMV was revealed in the right hippocampus, right fusiform gyrus (FFG), and temporal-parietal regions (the left superior/middle temporal gyrus, left operculo-insular gyrus, left inferior parietal lobule, and right inferior temporal gyrus) in patients with CTN. Increased functional activity measured by zALFF was observed mainly in the limbic system (the bilateral hippocampus and bilateral parahippocampal gyrus), bilateral FFG, basal ganglia system (the bilateral putamen, bilateral caudate, and right pallidum), left thalamus, left cerebellum, midbrain, and pons. Moreover, the right hippocampus and FFG were the overlapped regions with both functional and anatomical deficits. Furthermore, GMV in the right hippocampus was negatively correlated with pain intensity, anxiety, and depression. GMV in the right FFG was negatively correlated with illness duration. The zALFF value in the right FFG was positively correlated with anxiety.ConclusionOur results revealed concurrent structural and functional changes in patients with CTN, indicating that the CTN is a brain disorder with structural and functional abnormalities. Moreover, the overlapping structural and functional changes in the right hippocampus and FFG suggested that anatomical and functional changes might alter dependently in patients with CTN. These findings highlight the vital role of hippocampus and FFG in the pathophysiology of CTN.

Deficits in the thalamocortical pathway associated with hypersensitivity to pain in patients with frozen shoulder

“…Thalamus atrophy has been shown in various chronic pain conditions in prior investigations. Previous research studies have also shown that the thalamus anatomy was associated with neuropathic pain, and the level of atrophy was correlated with pain intensity in chronic pain patients (47)(48)(49)). An explanation for the atrophy of the gray matter in the thalamus could be the overactivation caused by excitotoxins and inflammatory agents (50-52).…”

The white matter characteristic of the genu of corpus callosum coupled with pain intensity and negative emotion scores in patients with trigeminal neuralgia: a multivariate analysis

“…Due to individual differences in pain intensity and negative emotion in patients with TN, the study of brain structure allows for a more direct correlation of changes with pain and negative emotion. There is ample evidence supporting the presence of white matter structural abnormalities in patients with TN ( Zhang et al, 2020 ; Liu et al, 2022 ). In our study, we identified white matter regions in the TN group with abnormally lower FA values including the genu of corpus callosum (CC), splenium of CC, tapetum of the CC, bilateral middle cerebellar peduncle (MCP), bilateral cerebral peduncle, left posterior thalamic radiation, bilateral anterior limb of internal capsule, and left posterior limb of internal capsule, compared with the HC group.…”

Alteration of brain network centrality in CTN patients after a single triggering pain

“…CTN is known as the most severe pain that humans can endure. Currently, most studies on the brain function of CTN patients are based on the cross-sectional rs-fMRI ( Xiang et al, 2019 ; Wu M. et al, 2020 ; Zhu et al, 2020 ; Li et al, 2021 ; Zhang et al, 2021 ; Liu et al, 2022 ). Several studies are based on the task state of TN with fewer subjects, including one case report which studied the local brain function ( Borsook et al, 2007 ).…”